EP3382199B1 - Nacelle for a wind turbine including a cooling circuit - Google Patents

Nacelle for a wind turbine including a cooling circuit Download PDF

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Publication number
EP3382199B1
EP3382199B1 EP17163103.9A EP17163103A EP3382199B1 EP 3382199 B1 EP3382199 B1 EP 3382199B1 EP 17163103 A EP17163103 A EP 17163103A EP 3382199 B1 EP3382199 B1 EP 3382199B1
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EP
European Patent Office
Prior art keywords
nacelle
stator
outlet
cooling circuit
inlet
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP17163103.9A
Other languages
German (de)
French (fr)
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EP3382199A1 (en
Inventor
Giovanni Airoldi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens Gamesa Renewable Energy AS
Original Assignee
Siemens Gamesa Renewable Energy AS
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens Gamesa Renewable Energy AS filed Critical Siemens Gamesa Renewable Energy AS
Priority to EP17163103.9A priority Critical patent/EP3382199B1/en
Priority to US15/933,492 priority patent/US10495068B2/en
Priority to CN201810258614.8A priority patent/CN108661865B/en
Publication of EP3382199A1 publication Critical patent/EP3382199A1/en
Application granted granted Critical
Publication of EP3382199B1 publication Critical patent/EP3382199B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D80/00Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
    • F03D80/60Cooling or heating of wind motors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D1/00Wind motors with rotation axis substantially parallel to the air flow entering the rotor 
    • F03D1/06Rotors
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D80/00Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
    • F03D80/80Arrangement of components within nacelles or towers
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D80/00Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
    • F03D80/80Arrangement of components within nacelles or towers
    • F03D80/82Arrangement of components within nacelles or towers of electrical components
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D80/00Details, components or accessories not provided for in groups F03D1/00 - F03D17/00
    • F03D80/80Arrangement of components within nacelles or towers
    • F03D80/88Arrangement of components within nacelles or towers of mechanical components
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03DWIND MOTORS
    • F03D9/00Adaptations of wind motors for special use; Combinations of wind motors with apparatus driven thereby; Wind motors specially adapted for installation in particular locations
    • F03D9/20Wind motors characterised by the driven apparatus
    • F03D9/25Wind motors characterised by the driven apparatus the apparatus being an electrical generator
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K1/00Details of the magnetic circuit
    • H02K1/06Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/22Rotating parts of the magnetic circuit
    • H02K1/32Rotating parts of the magnetic circuit with channels or ducts for flow of cooling medium
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K7/00Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/18Structural association of electric generators with mechanical driving motors, e.g. with turbines
    • H02K7/1807Rotary generators
    • H02K7/1823Rotary generators structurally associated with turbines or similar engines
    • H02K7/183Rotary generators structurally associated with turbines or similar engines wherein the turbine is a wind turbine
    • H02K7/1838Generators mounted in a nacelle or similar structure of a horizontal axis wind turbine
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K9/00Arrangements for cooling or ventilating
    • H02K9/02Arrangements for cooling or ventilating by ambient air flowing through the machine
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K9/00Arrangements for cooling or ventilating
    • H02K9/02Arrangements for cooling or ventilating by ambient air flowing through the machine
    • H02K9/04Arrangements for cooling or ventilating by ambient air flowing through the machine having means for generating a flow of cooling medium
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05BINDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2260/00Function
    • F05B2260/20Heat transfer, e.g. cooling
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/70Wind energy
    • Y02E10/72Wind turbines with rotation axis in wind direction

Definitions

  • the present invention relates to a nacelle for a wind turbine and therefore including an electrical generator driven by the blades of the wind turbine.
  • the nacelle also includes a cooling circuit for channeling a cooling medium to the generator.
  • the electrical generator and in particular the stator and the rotor has to be cooled, in order to optimize its efficiency and achieve the highest possible value of generated electrical power.
  • Various air cooling systems are known in the art for cooling the electrical generator in a nacelle for a wind turbine.
  • a nacelle for a wind turbine comprising an electrical generator having a stator and a rotor with an air gap between the stator and the rotor, the stator including an annular support plate, a cooling circuit including at least a first inlet portion for channeling a fluid cooling medium to the gap between the stator and the rotor, wherein the first inlet portion of the cooling circuit comprises at least an inlet hole on the annular support plate for letting at least a portion of the cooling medium flow towards the air gap.
  • the cooling circuit provided in the nacelle of the present invention comprises a first inlet portion which may be used for channeling a fluid cooling medium, in particular ambient air, from the outside of the nacelle to the air gap between the stator and the rotor, through an hole provided in the stator.
  • the first inlet portion may be provided, in possible embodiment of the present invention, with one or more filters for removing mist and ice from the fluid cooling medium. This allows to combine the advantages of the two air cooling system described with reference to the known prior art.
  • the stator includes a circumferentially outer structure attached to the annular support plate and the cooling circuit includes at least a second outlet portion for channeling an heated fluid medium from the gap between the stator and the rotor, the second outlet portion comprising at least an outlet hole on the circumferentially outer structure for letting the heated fluid medium flow from the air gap.
  • One or more additional holes are provided in the stator for channeling the fluid medium heated in the air between the stator and the rotor towards the outside of the nacelle. This helps in providing compact solution both for the electrical generator and the cooling circuit.
  • the circumferentially outer structure of the stator has a fork shape with two slanted portions departing from a circumferential border of the annular support plate, the outlet hole being provided on one of the slanted portions.
  • the circumferentially outer structure of the stator may be used with the double function of accommodating the stator segments and allowing the flow of the fluid medium heated in the air between the stator and the rotor.
  • the cooling circuit includes a bypass connecting the first inlet portion of the cooling circuit and the second outlet portion (120) of the cooling circuit.
  • One or more valves may be used in first inlet portion and/or the second outlet portion and/or in the bypass for controlling the flow of the cooling medium in the cooling circuit, in particular for controlling the amount of heated cooling medium flowing in the bypass.
  • the fluid medium heated in the air between the stator and the rotor may be used to be mixed with the fresh cooling medium entering the nacelle. This may help in reducing the humidity percentage of the cooling medium entering the nacelle with the purpose of facilitating the formation of salt crystals in the cooling medium, to be more easily stop before they reach the electrical generator.
  • FIG. 1 shows a wind turbine 1 having a nacelle 10 according to the invention.
  • the wind turbine 1 comprises a tower 2, which is mounted on a non-depicted fundament.
  • the nacelle 10 is arranged on top of the tower 2.
  • a yaw angle adjustment device is provided, which is capable of rotating the nacelle 10 around a not depicted vertical axis, which is aligned basically with the longitudinal extension of the tower 2.
  • a hub 9 having three blades (not represented in the attached drawings) is provided.
  • the hub 9 is rigidly coupled to a rotatable shaft 6.
  • a schematically depicted bearing assembly 7 is provided in the nacelle 10 in order to support the rotation of the rotatable shaft 6 and of the hub 9 coupled thereto, with respect to the body 8 of the nacelle 10.
  • the nacelle 10 comprises an electric generator 11, located at the front end of the nacelle 10 between the hub 9 and the body 8 of the nacelle 10.
  • the electric generator 11 comprises a stator assembly 20 and a rotor assembly 30.
  • the rotor assembly 30 is rigidly coupled to the rotatable shaft 6 and rotates solidly with it around the bearing assembly 7.
  • the stator assembly 20 is instead rigidly fixed to the body 8 of the nacelle 10.
  • an air gap 31 is provided between the stator assembly 20 and the rotor assembly 30. In operation the temperature in the air gap 31 rises. Such temperature has to be controlled beyond a limit to assure to keep the efficiency of the generator within acceptable values.
  • a cooling circuit 100 is provided for channeling a fluid cooling medium to the air gap 31 and channeling the same fluid cooling medium away from the air gap 31, after it has been heated in the air gap 31.
  • the fluid cooling medium extracts heat from the air gap 31.
  • the fluid cooling medium is ambient air surrounding the nacelle 10.
  • the cooling circuit 100 includes a first inlet portion 110 for channeling the fluid cooling medium to the air gap 31.
  • the inlet portion 110 extends from an inlet opening 130 in an outer wall 134 of the body 8 of the nacelle 10 to the air gap 31.
  • the inlet opening 130 is provided on a rear end of the body 8 of the nacelle 10, opposite to the hub 9.
  • a mist eliminator 133 is provided on the inlet opening 130 for reducing or eliminating the mist content in the fluid cooling medium entering the body 8 of the nacelle 10 through the inlet opening 130.
  • an inlet fan 140 is provided for making the fluid cooling medium flow in the inlet portion 110 of the cooling circuit 100. Downstream the inlet fan 140 a filter 150 is provided for blocking solid particles, for example dust and/or dust, contained in the fluid cooling medium.
  • the fluid cooling medium proceeds according to an axial flow (represented by the main arrow F in Figure 1 ) substantially parallel to the rotatable shaft 6.
  • This flow is divided downstream into two sub-flows, one flowing directly to the air gap 31 (represented by the arrow F1 in Figure 1 ) and the other (represented by the arrow F2 in Figure 1 ) flowing to the air gap 31 through a plurality of inlet holes 115 provided on an inner annular support plate 21 of the stator assembly 20.
  • the fluid cooling medium After being heated in the air gap 31, the fluid cooling medium enters the stator assembly 20 radially, i.e. according to a direction substantially orthogonal to the rotatable shaft 6 (represented by the arrows F3 in Figure 1 and 3 ).
  • the cooling circuit 100 includes a second outlet portion 120 for channeling the heated fluid medium away from the air gap 31.
  • the second outlet portion 120 comprises a plurality of outlet holes 125 arranged on a circumferentially outer structure 22 attached to the annular support plate 21 of the stator assembly 20. The outlet holes 125 let the heated fluid medium flow from away the air gap 31, in order to extract heat from the electrical generator 11.
  • the outlet portion 120 of the cooling circuit 100 Downstream the outlet holes 125, the outlet portion 120 of the cooling circuit 100 comprises a duct 160 connecting the outlet holes 125 to an outlet opening 131 provided on the outer wall 134 of the body 8 of the nacelle 10.
  • the outlet opening 131 is provided on a rear end of the body 8 of the nacelle 10, opposite to the hub 9. Through the outlet opening 131 the heated fluid medium is released in the ambient environment surrounding the nacelle 10.
  • an outlet fan 141 is provided between the outlet holes 125 and the outlet opening 131 for making the heated medium flow in the outlet portion 120 of the cooling circuit 100.
  • the cooling circuit 100 further includes a bypass 165 connecting the first inlet portion 110 and the second outlet portion 120 of the cooling circuit 100.
  • the bypass 165 is connected to the first inlet portion 110 between inlet opening 130 and the inlet fan 140.
  • the bypass 165 is connected to the second outlet portion 120 between the outlet fan 141 and the outlet opening 131.
  • Three valves 181, 182, 183 are respectively provided the first inlet portion 110, in the bypass 165 and in the second outlet portion 120 for controlling the flow of the cooling medium in cooling circuit 100.
  • the first valve 181 is provided the first inlet portion 110 of the cooling circuit 100, upstream the bypass 165, for controlling the flow of the cooling medium in the first inlet portion 110 and, in particular for closing the inlet portion 110 of the cooling circuit 100 in case of inactivity of the electrical generator 11.
  • the second valve 182 is provided the bypass 165 for controlling the flow of the heated cooling medium in the bypass 165. In this way the pre-heating of the cooling medium entering the first inlet portion 110 can be controlled.
  • the third valve 182 is provided the second outlet portion 120 of the cooling circuit 100, downstream the bypass 165, for controlling the flow of the cooling medium in the second outlet portion 120 and, in particular for closing the outlet portion 120 of the cooling circuit 100 in case of inactivity of the electrical generator 11.
  • FIGS 2 and 3 show in more detail the stator assembly 20.
  • the stator assembly 20 is an annular structure which is located in a concentric manner with regard to the rotational axis 6.
  • the stator assembly 20 comprises the inner annular support plate 21 which surrounds a non-depicted bearing assembly, which provides rotational support between the rotational axis 6 and the stator assembly 20.
  • the plurality of inlet holes 115 are provided on the inner annular support plate 21 of the stator 20, regularly distributed around an axis of the annular stator 20, i.e. regularly distributed around the rotational axis 6.
  • the circumferentially outer structure 22 is attached and surrounds the inner annular support plate 21.
  • the circumferentially outer structure 22 has a fork shape with two slanted portions 24, 26 departing from a circumferential border 27 of the annular support plate 21.
  • the circumferentially outer structure 22 of the stator 20 is used for accommodating the stator segments 28 each having several electric coils or windings 29. The entire circumference respectively the entire radially outer edge of the stator assembly 20 is covered with these stator segments 28.
  • the two slanted portions 24, 26 may be distinguished in a forward slanted portion 24 oriented towards the hub 9 and a rearward slanted portion 26 oriented in opposite direction towards the rear end of the body 8 of the nacelle 10.
  • the plurality of plurality of outlet holes 125 are provided on rearward slanted portion 26 of the stator 20, regularly distributed around an axis of the annular stator 20, i.e. regularly distributed around the rotational axis 6.

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  • Engineering & Computer Science (AREA)
  • Sustainable Energy (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Thermal Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Wind Motors (AREA)
  • Motor Or Generator Cooling System (AREA)

Description

    Field of invention
  • The present invention relates to a nacelle for a wind turbine and therefore including an electrical generator driven by the blades of the wind turbine. The nacelle also includes a cooling circuit for channeling a cooling medium to the generator.
  • Art Background
  • In the above described technical field, the electrical generator and in particular the stator and the rotor has to be cooled, in order to optimize its efficiency and achieve the highest possible value of generated electrical power. Various air cooling systems are known in the art for cooling the electrical generator in a nacelle for a wind turbine.
  • One possibility is to suck the cooling air from the outside and to direct it directly towards the generator. The main inconvenience of such solution is the moisture and salt content in the outside air, which causes corrosion in the generator, thus limiting its life. To avoid such inconvenience, a cooling circuit using the air already present inside the wind turbine may be formed. The efficiency of such solution may be however lower than the efficiency obtainable by using air from the outside ambient. Two examples known from the prior art are disclosed in US 2017/074251 A1 and EP 2 182 619 A1 .
  • There may be therefore still a need for providing a new nacelle including a cooling circuit for improving the cooling of the electrical generator, in terms of efficiency and the durability of the components inside the nacelle, in particular the generator.
  • Summary of the Invention
  • This need may be met by the subject matter according to the independent claims. Advantageous embodiments of the present invention are described by the dependent claims.
  • According to the invention there is provided a nacelle for a wind turbine comprising an electrical generator having a stator and a rotor with an air gap between the stator and the rotor, the stator including an annular support plate, a cooling circuit including at least a first inlet portion for channeling a fluid cooling medium to the gap between the stator and the rotor, wherein the first inlet portion of the cooling circuit comprises at least an inlet hole on the annular support plate for letting at least a portion of the cooling medium flow towards the air gap.
  • The cooling circuit provided in the nacelle of the present invention comprises a first inlet portion which may be used for channeling a fluid cooling medium, in particular ambient air, from the outside of the nacelle to the air gap between the stator and the rotor, through an hole provided in the stator. The first inlet portion may be provided, in possible embodiment of the present invention, with one or more filters for removing mist and ice from the fluid cooling medium. This allows to combine the advantages of the two air cooling system described with reference to the known prior art.
  • According to the present invention the stator includes a circumferentially outer structure attached to the annular support plate and the cooling circuit includes at least a second outlet portion for channeling an heated fluid medium from the gap between the stator and the rotor, the second outlet portion comprising at least an outlet hole on the circumferentially outer structure for letting the heated fluid medium flow from the air gap.
  • One or more additional holes are provided in the stator for channeling the fluid medium heated in the air between the stator and the rotor towards the outside of the nacelle. This helps in providing compact solution both for the electrical generator and the cooling circuit.
  • According to the invention the circumferentially outer structure of the stator has a fork shape with two slanted portions departing from a circumferential border of the annular support plate, the outlet hole being provided on one of the slanted portions.
  • Advantageously the circumferentially outer structure of the stator may be used with the double function of accommodating the stator segments and allowing the flow of the fluid medium heated in the air between the stator and the rotor.
  • According to a further embodiment the cooling circuit includes a bypass connecting the first inlet portion of the cooling circuit and the second outlet portion (120) of the cooling circuit.
  • One or more valves may be used in first inlet portion and/or the second outlet portion and/or in the bypass for controlling the flow of the cooling medium in the cooling circuit, in particular for controlling the amount of heated cooling medium flowing in the bypass.
  • Advantageously the fluid medium heated in the air between the stator and the rotor may be used to be mixed with the fresh cooling medium entering the nacelle. This may help in reducing the humidity percentage of the cooling medium entering the nacelle with the purpose of facilitating the formation of salt crystals in the cooling medium, to be more easily stop before they reach the electrical generator.
  • The aspects defined above and further aspects of the present invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment. The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.
  • Brief Description of the Drawing
  • Figure 1
    shows a schematic section of an upper of a wind turbine including a nacelle according to the present invention.
    Figure 2
    shows a stator structural element of the nacelle according to the present invention.
    Figure 3
    shows a stator assembly including the stator element of Figure 2.
    Detailed Description
  • The illustrations in the drawings are schematic. It is noted that in different figures, similar or identical elements or features are provided with the same reference signs or with reference signs, which are different from the corresponding reference signs only within the first digit. In order to avoid unnecessary repetitions elements or features which have already been elucidated with respect to a previously described embodiment are not elucidated again at a later position of the description.
  • Figure 1 shows a wind turbine 1 having a nacelle 10 according to the invention. The wind turbine 1 comprises a tower 2, which is mounted on a non-depicted fundament. The nacelle 10 is arranged on top of the tower 2. Between the tower 2 and a main body 8 of the nacelle 10 a yaw angle adjustment device is provided, which is capable of rotating the nacelle 10 around a not depicted vertical axis, which is aligned basically with the longitudinal extension of the tower 2. By controlling the yaw angle adjustment device in an appropriate manner it can be made sure, that during a normal operation of the wind turbine 1 the nacelle 10 is always properly aligned with the current wind direction.
  • On a front end of the body 8 of the nacelle 10, a hub 9 having three blades (not represented in the attached drawings) is provided.
  • The hub 9 is rigidly coupled to a rotatable shaft 6. A schematically depicted bearing assembly 7 is provided in the nacelle 10 in order to support the rotation of the rotatable shaft 6 and of the hub 9 coupled thereto, with respect to the body 8 of the nacelle 10.
  • The nacelle 10 comprises an electric generator 11, located at the front end of the nacelle 10 between the hub 9 and the body 8 of the nacelle 10. In accordance with the basic principles of electrical engineering the electric generator 11 comprises a stator assembly 20 and a rotor assembly 30.
  • The rotor assembly 30 is rigidly coupled to the rotatable shaft 6 and rotates solidly with it around the bearing assembly 7. The stator assembly 20 is instead rigidly fixed to the body 8 of the nacelle 10. Around a circumferentially border of the stator assembly 20 an air gap 31 is provided between the stator assembly 20 and the rotor assembly 30. In operation the temperature in the air gap 31 rises. Such temperature has to be controlled beyond a limit to assure to keep the efficiency of the generator within acceptable values.
  • To achieve such scope, inside the body 8 of the nacelle 10 a cooling circuit 100 is provided for channeling a fluid cooling medium to the air gap 31 and channeling the same fluid cooling medium away from the air gap 31, after it has been heated in the air gap 31. In such a way the fluid cooling medium extracts heat from the air gap 31. According to a typical embodiment of the present invention, the fluid cooling medium is ambient air surrounding the nacelle 10.
  • The cooling circuit 100 includes a first inlet portion 110 for channeling the fluid cooling medium to the air gap 31.
  • The inlet portion 110 extends from an inlet opening 130 in an outer wall 134 of the body 8 of the nacelle 10 to the air gap 31. According to the embodiment of figure 1, the inlet opening 130 is provided on a rear end of the body 8 of the nacelle 10, opposite to the hub 9. On the inlet opening 130 a mist eliminator 133 is provided for reducing or eliminating the mist content in the fluid cooling medium entering the body 8 of the nacelle 10 through the inlet opening 130.
  • Downstream the mist eliminator 133 an inlet fan 140 is provided for making the fluid cooling medium flow in the inlet portion 110 of the cooling circuit 100. Downstream the inlet fan 140 a filter 150 is provided for blocking solid particles, for example dust and/or dust, contained in the fluid cooling medium.
  • Downstream the filter 150 the fluid cooling medium proceeds according to an axial flow (represented by the main arrow F in Figure 1) substantially parallel to the rotatable shaft 6. This flow is divided downstream into two sub-flows, one flowing directly to the air gap 31 (represented by the arrow F1 in Figure 1) and the other (represented by the arrow F2 in Figure 1) flowing to the air gap 31 through a plurality of inlet holes 115 provided on an inner annular support plate 21 of the stator assembly 20.
  • After being heated in the air gap 31, the fluid cooling medium enters the stator assembly 20 radially, i.e. according to a direction substantially orthogonal to the rotatable shaft 6 (represented by the arrows F3 in Figure 1 and 3).
  • The cooling circuit 100 includes a second outlet portion 120 for channeling the heated fluid medium away from the air gap 31. The second outlet portion 120 comprises a plurality of outlet holes 125 arranged on a circumferentially outer structure 22 attached to the annular support plate 21 of the stator assembly 20. The outlet holes 125 let the heated fluid medium flow from away the air gap 31, in order to extract heat from the electrical generator 11.
  • Downstream the outlet holes 125, the outlet portion 120 of the cooling circuit 100 comprises a duct 160 connecting the outlet holes 125 to an outlet opening 131 provided on the outer wall 134 of the body 8 of the nacelle 10. According to the embodiment of figure 1, the outlet opening 131 is provided on a rear end of the body 8 of the nacelle 10, opposite to the hub 9. Through the outlet opening 131 the heated fluid medium is released in the ambient environment surrounding the nacelle 10.
  • Between the outlet holes 125 and the outlet opening 131 an outlet fan 141 is provided for making the heated medium flow in the outlet portion 120 of the cooling circuit 100.
  • The cooling circuit 100 further includes a bypass 165 connecting the first inlet portion 110 and the second outlet portion 120 of the cooling circuit 100. The bypass 165 is connected to the first inlet portion 110 between inlet opening 130 and the inlet fan 140. The bypass 165 is connected to the second outlet portion 120 between the outlet fan 141 and the outlet opening 131. The mixing of the fresh cooling medium entering the nacelle 10 with the heated cooling medium flowing from the air gap 31 provides a preheating of the fluid cooling medium in the first inlet portion 110 and a reduction of the value of relative humidity. A lower value of relative humidity may facilitate the formation of ice crystals in the humid air entering the nacelle. Such ice crystals are then more easily blocked in the filter 150, so that they are prevented from reaching the electrical generator 11.
  • Three valves 181, 182, 183 are respectively provided the first inlet portion 110, in the bypass 165 and in the second outlet portion 120 for controlling the flow of the cooling medium in cooling circuit 100.
  • The first valve 181 is provided the first inlet portion 110 of the cooling circuit 100, upstream the bypass 165, for controlling the flow of the cooling medium in the first inlet portion 110 and, in particular for closing the inlet portion 110 of the cooling circuit 100 in case of inactivity of the electrical generator 11.
  • The second valve 182 is provided the bypass 165 for controlling the flow of the heated cooling medium in the bypass 165. In this way the pre-heating of the cooling medium entering the first inlet portion 110 can be controlled.
  • The third valve 182 is provided the second outlet portion 120 of the cooling circuit 100, downstream the bypass 165, for controlling the flow of the cooling medium in the second outlet portion 120 and, in particular for closing the outlet portion 120 of the cooling circuit 100 in case of inactivity of the electrical generator 11.
  • Figures 2 and 3 show in more detail the stator assembly 20.
  • The stator assembly 20 is an annular structure which is located in a concentric manner with regard to the rotational axis 6. The stator assembly 20 comprises the inner annular support plate 21 which surrounds a non-depicted bearing assembly, which provides rotational support between the rotational axis 6 and the stator assembly 20.
  • The plurality of inlet holes 115 are provided on the inner annular support plate 21 of the stator 20, regularly distributed around an axis of the annular stator 20, i.e. regularly distributed around the rotational axis 6.
  • The circumferentially outer structure 22 is attached and surrounds the inner annular support plate 21.
  • The circumferentially outer structure 22 has a fork shape with two slanted portions 24, 26 departing from a circumferential border 27 of the annular support plate 21. The circumferentially outer structure 22 of the stator 20 is used for accommodating the stator segments 28 each having several electric coils or windings 29. The entire circumference respectively the entire radially outer edge of the stator assembly 20 is covered with these stator segments 28.
  • The two slanted portions 24, 26 may be distinguished in a forward slanted portion 24 oriented towards the hub 9 and a rearward slanted portion 26 oriented in opposite direction towards the rear end of the body 8 of the nacelle 10.
  • The plurality of plurality of outlet holes 125 are provided on rearward slanted portion 26 of the stator 20, regularly distributed around an axis of the annular stator 20, i.e. regularly distributed around the rotational axis 6.
  • It should be noted that the term "comprising" does not exclude other elements or steps and the use of articles "a" or "an" does not exclude a plurality. Also elements described in association with different embodiments may be combined. Z
  • The scope of protection is defined by the claims. should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

Claims (12)

  1. A nacelle (10) for a wind turbine (1) comprising
    an electrical generator (11) having a stator (20) and a rotor (30) with an air gap (31) between the stator (20) and the rotor (30), the stator (20) including an annular support plate (21),
    a cooling circuit (100) including at least a first inlet portion (110) for channeling a fluid cooling medium to the air gap (31) between the stator (20) and the rotor (30),
    wherein the first inlet portion (110) of the cooling circuit (100) comprises at least an inlet hole (115) on the annular support plate (21) for letting at least a portion of the cooling medium flow towards the air gap (31) the stator (20) includes a circumferentially outer structure (22) attached to the annular support plate (21) and
    the cooling circuit (100) includes at least a second outlet portion (120) for channeling an heated fluid medium from the air gap (31) between the stator (20) and the rotor (30), the second outlet portion (120) comprising at least an outlet hole (125) on the circumferentially outer structure (22) for letting the heated fluid medium flow from the air gap (31)
    characterized in that the circumferentially outer structure (22) has a fork shape with two slanted portions (24, 26) departing from a circumferential border of the annular support plate (21), the outlet hole (125) being provided on one of the slanted portions (26).
  2. The nacelle (10) of claim 1, wherein the first inlet portion (110) of the cooling circuit (100) comprises a filter (150) upstream the stator inlet hole (115).
  3. The nacelle (10) of claim 2, wherein the first inlet portion (110) of the cooling circuit (100) comprises an inlet fan (140) upstream the filter (150).
  4. The nacelle (10) of claim 3, wherein first inlet portion (110) of the cooling circuit (100) comprises an inlet opening (130) in an outer wall (134) of the nacelle (10) upstream the inlet fan (140).
  5. The nacelle (10) of claim 1, wherein the second outlet portion (120) of the cooling circuit (100) comprises an outlet opening (131) in an outer wall of the nacelle (10) and a duct (160) connecting the outlet hole (125) on the circumferentially outer structure (22) to the outlet opening (131) .
  6. The nacelle (10) of any of the previous claims 3 to 5, wherein the cooling circuit (100) includes a bypass (165) connecting the first inlet portion (110) of the cooling circuit (100) and the second outlet portion (120) of the cooling circuit (100).
  7. The nacelle (10) of claim 6, wherein the bypass (165) is connected to the first inlet portion (110) between the inlet opening (130) and the inlet fan (140).
  8. The nacelle (10) of claim 6 or 7, wherein the second outlet portion (120) comprises an outlet fan (141), the bypass (165) being connected to the second outlet portion (120) between the outlet fan (141) and the outlet opening (131) .
  9. The nacelle (10) of claim 7 or 8, wherein at least a valve (181, 182, 183) in first inlet portion (110) and/or the second outlet portion (120) and/or in the bypass (165) for controlling the flow of the cooling medium in the cooling circuit (100).
  10. The nacelle (10) of any of the previous claims, wherein a plurality of inlet holes (115) is provided on the stator (20), distributed around an axis of the stator (20).
  11. The nacelle (10) of any of the previous claims, wherein a plurality of plurality of outlet holes (125) is provided on the stator (20), distributed around an axis of the stator (20) .
  12. The nacelle (10) of any of the previous claims, wherein the stator (20) is coaxial with the rotor (30).
EP17163103.9A 2017-03-27 2017-03-27 Nacelle for a wind turbine including a cooling circuit Active EP3382199B1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP17163103.9A EP3382199B1 (en) 2017-03-27 2017-03-27 Nacelle for a wind turbine including a cooling circuit
US15/933,492 US10495068B2 (en) 2017-03-27 2018-03-23 Nacelle for a wind turbine including a cooling circuit
CN201810258614.8A CN108661865B (en) 2017-03-27 2018-03-27 Nacelle for a wind turbine comprising a cooling circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP17163103.9A EP3382199B1 (en) 2017-03-27 2017-03-27 Nacelle for a wind turbine including a cooling circuit

Publications (2)

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EP3382199A1 EP3382199A1 (en) 2018-10-03
EP3382199B1 true EP3382199B1 (en) 2023-12-20

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Also Published As

Publication number Publication date
CN108661865A (en) 2018-10-16
US10495068B2 (en) 2019-12-03
EP3382199A1 (en) 2018-10-03
CN108661865B (en) 2020-08-11
US20180274522A1 (en) 2018-09-27

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